Automatic doffing and donning



April 24, 1962 EIZABURO NEGISHI 3,030,761

AUTOMATIC DOFFING AND DONNING Filed Aug. 23, 1960 4 Sheets-Sheet 1 April 24, 1962 EIZABURO NEGISHI 3,030,761

Y AUTOMATIC DOFFING AND DONNING Filed Aug. 23, 1960 4 Sheets-Sheet 2 April 1962 EIZABURO NEGISHI 3,030,761

AUTOMATIC DOFFING AND DONNING 4 Sheets-Sheet 3 Filed Aug. 23, 1960 April 24, 1962 EIZABURO NEGlSHi AUTOMATIC DOFFING AND DONNING 4 Sheets-Sheet 4 Filed Aug. 23, 1960 III United States Patent Ofiice Bfifihflhl Patented Apr. 24, 1962 3,030,761 AUTQMATIC DOFFING AND DQNNING Eizaburo Negishi, 3 of No. 9 Oaza Nakazato, Yono-shi, Saitarna-ken, Japan Filed Aug. 23, 1969, Ser. No. L37 Claims priority, application Japan Sept. 10, 1959 12 Qlaians. (Cl. 57-52) The present invention relates to an automatic spinning, twisting and analogous machine and more particularly to an automatic centrifugal spinning machine which can be operated automatically at high efficiency.

The use of centrifugal spinning machine has drawn the attention of the spinning industry because of its high speed operation and the specific characteristics of the quality of the thread obtained. However, it has been necessary with known centrifugal spinning machine to require some manual operations which hinder the high efiiciency of the apparatus. Applicant has developed an automatic spinning machine in which all the operations including spinning, rewinding and dofling can be automatically carried out and the efiiciency can be greatly improved.

The apparatus of the present invention can be utilized in spinning, twisting and analogous machines whether the fiber thereof is cotton, wool, or synthetic.

The automatic spinning machine of the present invention has a spinning and rewinding device comprising a yarn-guide tube on which a bobbin is mounted, and a concentrical spinning tube surrounding the bobbin and adapted to be rotated at a high speed, a doffing device comprising a bobbin carrier tube and a ring member slidably movable by a shaft in said bobbin carrier tube, a magazine where an empty bobbin is stored for replacement, a device for removing the doifing device from a position directly below the spinning and rewinding device to a position directly below the magazine to receive an empty bobbin therefrom and returning the dofiing device to the original position below the spinning and rewinding device, and a device for coordinating the operations of various elements so that the spinning, rewinding and doffing operations can be automatically and smoothly carried out.

The object of the present invention is to make all the operations of a spinning machine including spinning, rewinding and doffing automatic thereby improving the efliciency thereof.

Another object of the present invention is to provide means which enables a bobbin doifed from the apparatus to be transported in a guideway automatically.

Another object of the present invention is to provide means which detects break of a yarn during a rewinding operation onto a bobbin from a cake in the spinning tube and which automatically restarts the rewinding operation.

Another object of the present invention is to provide means which promotes constant air flow from the yarn guide tube to the spinning tube during the spinning period, in order to prevent entanglement of a yarn within the spinning tube which often occurs with a conventional centrifugal spinning machine and affects the quality of the product and the efficiency.

The above described and other features and advantages of the present invention will be made clear from the following detailed explanations of the embodiment of the present invention with reference to the accompanying drawings in which:

FIG. 1 is a schematic cross sectional view of an automatic spinning machine according to the present invention during the spinning operation, some parts being omitted for clarity;

FIG. 2 is a view of the machine of FIG. 1 partly shown in cross section, illustrating the condition where the spinning operation has been completed and the rewinding operation is about to start;

FIG. 3 is a schematic view of the machine of FIG. 1 partly in section illustrating the condition where the device for replacing a bobbin is moved from the position below the spinning and rewinding device to the position below the magazine to receive an empty bobbin while a full bobbin (cop) is dropped from the yarn guide tube onto a guideway;

FIG. 4 is a view of the machine of FIG. 1 partly in section illustrating the condition where the device for replacing a bobbin has been returned to the original position and the bobbin is about to be mounted on the yarn guide tube;

FIG. 5 is a diagrammatic view illustrating a system for coordinating the operations of the various elements of the apparatus;

FIG. 6 is a schematic view illustrating the operation of a doffing Wheel of the present invention; and

FIG. 7 is a schematic sectional view illustrating on a larger scale the construction of a bobbin support provided with a circular knife edge.

As shown in FIG. 1, the machine of the present invention has three main parts, a spinning and rewinding device generally indicated by A, a doffing and bobbin replacing device generally indicated by B and a magazine for delivery of an empty bobbin generally indicated by C.

The spinning and rewinding device A has a fixed outer casing 12 in which a spinning tube 11 is rotatably mounted. In the center of the casing 12 is provided a hollow yarn guide tube 3 which is fixed on and suspended from a rail 4 movable up and down to give a reciprocating motion to the hollow yarn guide tube 3. The spinning tube 11 has an upper neck 9 of a smaller diameter and a flange N which is supported by a pair of pulleys 41, 42. The neck 9 of the spinning tube 11 bears against the upper pulleys 41, 42 and lower pulleys 41', 42 and an endless tape 43 is hung around the neck 9.

The spinning tube 11 is rotated by said tape 43 which is driven by a motor (not shown) at a high speed while the yarn guide tube 3 is moved up and down by means of the rail 4. A strand of yarn from front rollers l is introduced into the yarn guide tube 3 through its top opening 2. and is sucked into said tube and blown onto the internal surface of the spinning tube 11 and wound thereon under the influence of the blowing air and the centrifugal force caused by the rapid rotation of the spinning tube 11.

When the yarn has been wound fully and has formed cake 32 on the internal surface of the spinning tube, the yarn guide tube 3 is lowered to the bottom to pinch the yarn 811 between the outer wall end of .a bobbin 6 mounted on the yarn guide tube 3 and an elastic ring member 20 supported by a shaft 21 which will be explained hereinafter. The yarn guide tube 3 and the bobbin 6 are now maintained stationary, and the motions of the front rollers 1 and the rail 4 are stopped while the spinning tube 11 continues to rotate. Under this condition, the yarn of cake 32 on the internal surface of the spinning tube 11 is rewound onto the bobbin 6 to form a cop 33 on the bobbin. In FIG. 2, a cop under formation and not yet completed is shown by 33.

During the rewinding of the yarn from the cake 32 onto the bobbin 6, the yarn might break. The apparatus of the present invention has a feeler 22 (FIG. 2) which is reciprocated up .and down by cooperation of a spring 1'7 urging the feeler 22 upward and a tape 29 periodically pulling the stem 23 of the feeler 22 downward. When the yarn 3a being rewound onto the bobbin 6 is broken, the cake 32 of yarn on the internal surface of the spinning tube has a constant thickness, and

hence the tip end of the feeler 22 which is raised higher and higher as the time of rewinding proceeds will prod the cake to catch the end of the broken yarn as it goes up and the end of-the yarn is restarted to be rewound on the bobbin 6. This detection of the broken yarn end of the cake and the restart of rewinding of the yarn is known per se in the art and does not need any further explanation.

When the yarn is rewound fully on the bobbin 6 said bobbin must be replaced by an empty bobbin 6a. replacement of the bobbin is carried out by the bobbin replacement device B. The device B has a bobbin carrier tube 18 and a shaft 21 slidably mounted in said bobbin carrier tube 18. The top end of the bobbin carrier tube 18 flares to form a flange 19 which closes the bottom end opening of the spinning tube 11 leaving a clearance S. This clearance is small enough to prevent admission of air into the spinning tube while allowing the discharge of air introduced into the yarn guide tube 3 through its top opening 2 during the spinning operation, and thus a constant flow of air from the lower end of the yarn guide tube 3 towards the internal surface of the spinning tube 11 is maintained to facilitate the spinning of the yarn onto the internal surface of the spinning tube 11.

The shaft 21 has an elastic ring member 20 (see FIG. 7) which is supported on a flange 15' of a sleeve 15 slidably and elastically mounted on a tube member 15" which is fixed on the top of the shaft 21 by means of a ring member 15" and a spring 37 which is provided etween the flange 15 of the slidable sleeve 15 and'the fixed ring member 15". The shaft 21 has also an elastic central member 20' surrounded by a circular knife edge 16 fixed on the top as shown in FIG. 7. The knife edge 16 projects above the levels of the elastic ring member 20 and the elastic central member 20'. Accordingly it is apparent that the yarn 812 will be cut by the knife edge 16 and one of the cut ends will be caught between the bobbin 6 and the ring member 20 while the other cut end be caught between the end of the yarn guide tube 3 and the central support 20' when the yarn guide tube 3 is lowered together with the bobbin against the members This 29 and 20'. The presence of the end of the yarn at the 1 end of the yarn guide tube 3 will facilitate the next succeeding spinning operation when it is started.

The following shows how the replacement of the full bobbin on the yarn guide tube 3 for an empty bobbin is made.

For this purpose, the bobbin carrier tube 18 is supported by a bracket 24 which is fixed on a slidable and rotatable shaft 25.

As shown in FIG. 3, when the rewinding of the yarn onto a bobbin 6 is completed in the device A, the shaft 25 is operated to slide and to rotate to bring the bobbin carrier tube 18 together with its associated members such as the central slidable shaft 21 and the feeler 22 below a magazine 31 which is fixed by a bracket to the apparatus and holds an empty bobbin 6a by an elastic hook 38 operable by a lever 39. When the bobbin carrier tube 18 comes below the magazine 31, the flange 19 of the tube 18 operates the lever 39 to release the empty bobbin 6a thereby allowing it to drop into the bobbin carrier tube 18 in which the slidable shaft 21 is lowered together with its top members 29 and 2%. On the other hand, during the motion of the bobbin carrier tube 18 above described, the rail 4 is raised to lift the yarn guide tube 3 together with the full bobbin thereon. On the top portion of the device A, a tube 13 (see FIG. 1) is fixed between the top portion of the spinning tube 11 and the top collar portion 5 of the yarn guide tube 3 which has the same diameter as thebobbin 6, leaving some clearance so that the rotation of the neck 9 of the spinning tube 11 and the sliding motion of the yarn guide tube 3 will not be interfered with by tube 13.

When the yarn guide tube 3 having a full yarn cop 33 thereon is raised, the cop abuts against the lower end of the tube 13 and the cop is pressed downward by the tube 13.

The bobbin 6 is supported on the yarn guide tube 3 by means of a spring book 7 which can be pressed down when the tube 3 is further raised leaving the bobbin 6 free to drop. The bobbin carrier tube 18 and the supports 29, 20 have been moved aside but a slide guideway 26 fixed on the side of the bobbin carrier tube 18 is adapted to come below the device A when said tube 18 is moved aside, and consequently the cop 33 drops on said guideway 26 to be passed onto a conveyor 35 operated by rollers 36 as shown in FIG. 3 to be carried away to any desired place.

The bobbin carrier tube 18 which has received an empty bobbin 6a is now returned to the original position below the spinning and winding device A, and the shaft 21 is raised by means of an arm 39 to push the empty bobbin 6a onto the yarn guide tube 3 which has been lowered to the bottom position after the removal of the cop 33. When the bobbin 6:; is raised up to the spring hook 7, the bobbin is fixed on the yarn guide tube 3 for the next spinning and rewinding operation. While the bobbin 6 is shown to be detachably supported on the yarn guide tube 3 by means of a spring book 7, the means for the detachable support of the bobbin is of course not limited to a spring hook, and any other means suitable for the purpose can be used. For instance, the top portion of the yarn guide tube 3 may be magnetic which attracts and supports the bobbin by a magnetic force but allows the detachment of the bobbin therefrom when the yarn guide tube 3 is raised and the cop 33 wound on the bobbin 6 abuts against the lower end of the tube 13.

The above are the operations of the various elements of the present apparatus for carrying out the automatic spinning, rewinding and dofiing operations. However, for accomplishing such automatic operations, there must be a device for coordinating various operations of various elements orderly and smoothly. Explanation of such a device follows.

According to the present invention, the elements of the apparatus are driven by three driving systems and a device is provided for interlocking the three driving systerns.

The first driving system controls the elements which are operated only during the spinning period. The front rollers 1 and the rail 4 which moves up and down to give a traverse motion to the yarn guide tube are controlled by the first driving system.

The second driving system controls the element which is operated not only during the spinning period but also during the period in which the yarn of the cake on the internal surface of the spinning tube 11 is rewound on the bobbin 6 mounted on the yarn guide tube 3.

The third driving system controls the operation of the device for the replacement of the bobbin and particularly the motion of the bobbin carrier tube 18 and the shaft 21 adapted to support the yarn guide tube 3 and the bobbin 6 mounted thereon. The third driving system also controls the motion of the feeler 22 operated during the rewinding operation on the bobbin.

Of these three driving systems, the second system is quite simple, since the required operation is to rotate the spinning tube 11 during the spinning period and the winding period of the yarn on the bobbin 6 continuously. For this driving system, a motor (not shown) is provided to drive a belt 43. However, the motions of the various elements driven by the first driving system and the third driving system are more complicated and the coordination of these motions cannot be achieved so readily. The solution of this problem is one of the important aspects of the present invention.

FIG. 5 illustrates the first and the third driving systems and coordination of the two systems. In the drawing, 56

represents a reversible motor of which the direction of rotation is controlled by an electro-magnetic switch 51 and 52 is a shaft rotated by the motor 50. On said shaft are fixedly mounted a wheel 55 and a ratchet holder 53 provided with ratchet 54 on its circumference. The ratchet holder 53 transmits the rotation to a wheel 56 only when it is rotated in the normal direction, and this wheel 56 is utilized as the prime mover for the first driving system. It is seen in the drawing that the front roller li driven by a gear system comprising gears 56, 58, 59, 69', 61, 62, a chain wheel 63, 64 and gears 65, 66. During the spinning period, the rail 4 must be reciprocated up and down thereby to give the yarn guide tube 3 traverse motion. For this purpose, a gear 67 is fixed on the shaft of the gear 62 and the rotation of the gear 67 is transmitted to a worm wheel 72 through gears 68, bevel gears 69, 70 and a worm 71, and on the shaft of the worm wheel 72 is fixed a cam '73. A roller 74 mounted on a lever 75 rotatably supported on a fixed shaft 76 is in contact with the cam 73 and the lever '75 is moved up and down when the cam 73 is rotated. A ratchet 89 is fixed at the free end of the lever 75 and acts to rotate a shaper wheel 79 which has a worm 78 on the shaft. When the shaper wheel 79 is rotated, a worm wheel 77 in engagement with the worm 78 is rotated to operate the drum 81 to unwind the chain 83 to change the basic position of the rail 4 which is traversing as known in the art.

From the above, it will be apparent that the rotation of the front rollers 1 and the traverse motion of the yarn guide tube 3 are carried out as the motor 561 is rotated in normal direction. The direction of the rotation of the motor 50 is reversed by the electro-magnetic switch 51 which is operated when the yarn is fully Wound on the internal surface of the spinning tube 11.

For this purpose, for instance, an auto-counter of the front roller 1 which acts on the switch 51 when the numnumber of the rotation of the roller 1 reaches a predetermined number or a time limiting device which indirectly define the size of the cake 32 by the time of operation may be utilized. In the embodiment of the illustration, however, a special rod 138 (see FIG. 6) is associated with the rail 4 and, when the rail 4 is lowered fully by the action of the chain 83, that is, when the yarn is fully wound on the internal surface of the spinning tube 11, a lever 130 pivoted on the rod 138 is brought below the projection 131 of a lever 129 which is rotatable around a pin 125 and when the rod 138 is raised by the rail 4, the lever 130 acts to lift the projection '131 rotating the lever 129 since the lever 130 is so arranged that it cannot rotate clockwise by means of a stop provided below the lever 139. The projection 131 is fixed with a screw 126 which operates a switch 127. This switch is connected to the electro-magnetic switch 51 which controls the direction of the rotation of the motor 50.

Accordingly when yarn is fully wound on the internal surface of the spinning tube 11, the rotation of the motor will be reversed and the rewinding will begin. When the rewinding of yarn onto the bobbin 6 is completed and then the bobbin 6 is replaced for an empty bobbin by the doffing device B, the rotation of the motor 50 shall be returned to normal direction. This is performed by a control wheel 122 provided with a notch 124 on its circunrference 123. This wheel 122 is adapted to be rotated by a doffing wheel 98 which completes one rotation during the period from the start of the rewinding of the yarn from the spinning tube 11 onto the bobbin 6 mounted on the yarn guide tube 3 to the completion of the return of the doffing device B below the spinning and rewinding device A and mounting an empty bobbin onto the yarn guide tube 3 as explained hereinafter. As seen from FIG. 6, once the lever 129 is raised and the projection 128 gets out of the notch 124, the lever 129 cannot return to the lowered position since the projection 128 rests on the circumference 123 of the control wheel until said wheel completes one rotation to bring the notch 124 below the projection 128. Thus the rotation of the motor 50 is maintained in reversed direction until the start of the subsequent spinning operation.

Now the construction of the third driving system will be explained. When the motor 50 is driven in reversed direction (see FIG. 6), the gear 57 and ratchet wheel 56 are not rotated any longer, but a chain wheel 55 is rotated to rotate a chain wheel 91 through a chain 90. Now gears 92, 93 are rotated. This gear 93 has a ratchet gear 94 along the internal circumference of its rim to rotate a ratchet holder 96 when it is rotated in reversed direction by the engagement of the ratchet 95 of the ratchet holder 96 with the ratchet gear 94. Thus the ratchet holder 96 is rotated only when the motor 50 is rotated in reversed direction. This ratchet holder 96 is utilized as the prime mover for the third driving system. The rotation of the ratchet holder 96 is transmitted to a worm 97 to rotate a dofling Wheel 98. The doffing wheel 98 has a shaft 99 on which cams 101, 102 and 103 (see FIG. 6) are fixed. The cam 101 controls the motion of the shaft 25 supporting the bobbin carrier tube 18, While the cam 102 controls that of the belt 29 and the cam 103, that of the arm 30 supporting the shaft 21. As seen from FIG. 6, when the cam 101 is rotated, the shaft 25 is at rest at the beginning of rotation, but is subsequently shifted to the left and then returned to the original position by means of a lever 112 which has a roller 111 in contact with the cam 191 and another roller 114 in engagement with the shaft 25. The shaft 25 has a projection in engagement with a helical groove 136 and hence rotates when it is shifted to side. Thus the movement of the bobbin carrier tube 18 from the position of FIG. 1 to the position of FIG. 3 and its return to the original position can be achieved.

The cam 102 has a number of parts corresponding to the motions of the feeler 22 and a part thereof corresponding to the traverse motion has saw-teeth 1114 as shown in FIG. 6. This cam pulls a belt 29 (see FIGS. 2 and 3) and slackens it to give up and down motion to the feeler 22 through its stem 23 to which the belt 29 is connected. This operation is conducted during the period of rewinding the yarn onto the bobbin 6 mounted on the yarn guide tube 3 in addition to the general motion of rising according to the general curvature of the cam. The cam 103 has a shape as shown in FIG. 6 and controls the motion of the arm 30. When the bobbin carrier tube 18 is brought below the magazine 31, the arm 30 is not only lowered, but it is displaced from the end of the shaft 21 and therefore the shaft 21 is allowed to descend by its weight to receive an empty bobbin 6a from the magazine 31 as shown in FIG. 3. When the bobbin carrier tube 18 is returned to the position below the spinning tube 11, the arm 30 is raised to push the empty bobbin 6 into the spinning tube 11 onto the yarn guide tube 3 until said bobbin is locked by the spring hook 7 on the yarn guide tube 3.

Now, the apparatus is returned to the original position to restart the spinning operation on the internal surface of the spinning tube.

As explained before, the rotation of the dofiing wheel 98 and the control wheel is completed and the notch 124 of the control wheel 122 is brought below the projection 128 of the lever 129 to establish the contact between the screw 126 and the switch 127.

Consequently the electro-magnetic switch 51 is operated to return the direction of the rotation of the motor 50 to normal, and the spinning operation as described above will be automatically restarted.

As explained above, all operations including spinning, rewinding and dofi'lng can be achieved automatically according to the present invention and the efficiency of spinning will be greatly increased.

What I claim is:

1. Apparatus for the automatic winding of yarn comprising a spinning tube adapted for rotation, a yarn guide tube slidable in said spinning tube, said yarn guide tube directing feed of the yarn to said spinning tube, a bobbin on said yarn guide tube adapted to be wound with yarn from said spinning tube, dofiing and bobbin replacing means comprising a bobbin carrier tube coaxial with the yarn guide tube and pivotable with respect thereto, an elastic ring member slidably supported in said carrier tube, an empty bobbin for replacing the bobbin wound with yarn, and magazine means for delivering the empty bobbin to said carrier tube; means for sliding the yarn guide tube into contact with the elastic ring member to interrupt the feed of yarn to said spinning tube whereupon said spinning tube feeds the yarn to said bobbin, means for pivoting the bobbin carrier tube to a position adjacent the magazine means to receive said empty bobbin therefrom, means for discharging the bobbin wound with yarn from the yarn guide tube with said bobbin carrier tube adjacent the magazine means, and means for returning said bobbin carrier tube to the position coaxial with said yarn guide tube to mount said empty bobbin thereon.

2. Apparatus as claimed in claim 1 comprising a tube between the yarn guide tube and the spinning tube for engaging yarn which is wound on said bobbin for detaching the yarn from said yarn guide tube upon raising of the latter.

3. Apparatus as claimed in claim 1 comprising means for driving the apparatus and means for reversing the direction of rotation of the last said means comprising a special rod coupled to said yarn guide tube and movable therewith, a lever on said rod, a switch for controlling the direction of said first means, said lever being adapted to control said switch, and a control wheel which is rotated with said first means rotating in reversed direction, the control wheel being operatively associated with said switch to position the same to maintain reversed rotation of said first means, said wheel being provided with a notch, a second lever operatively associated with the first said lever to displace the same to change the direction of rotation of the first said means from reverse to normal with the second lever engaged in said notch.

4. Apparatus as claimed in claim 1 comprising means for automatically controlling movement of the spinning tube, yarn guide tube and bobbin and doffing means comprising; a wheel, a ratchet on said wheel, a gear operatively coupled to said ratchet for rotation with said wheel rotated in a normal direction, front rollers for feeding yarn to said spinning tube, gear means coupled to said gear, said front rollers being coupled to said gear means for being driven thereby, a cam rotatable with said gear means and controlling displacement of the yarn guide tube, and a further gear which is rotated with the wheel being rotated in reversed direction, a shaft coupled to said further gear and rotatable therewith, and at least one cam on said shaft coupled to said dofiing means for controlling the same.

5. Apparatus as claimed in claim 1 comprising a housing for said spinning tube and said yarn guide tube, a flange on said bobbin carrier tube adjacent the bottom of said housing and defining a space therebetween, whereby air which is admitted to said housing through said yarn guide tube escapes through said space under the influence of the rotation of said spinning tube.

6. Apparatus as claimed in claim 1 comprising a circumferential elastic member on said carrier tube for contacting the bobbin on said yarn guide tube and cutting means on said carrier tube between the elastic ring member and the circumferential member and projecting thereabove, so that the cutting means is adapted to cut the yarn, the yarn, with the same out being retained between the bobbin and the circumferential member and the yarn guide tube and ring member respectively.

7. Apparatus as claimed in claim 1 comprising a shaft, an arm fixed on said shaft and supporting said bobbin carrier tube, the shaft being rotatable and displaceable to pivot the bobbin carrier tube to said position adjacent the magazine means to receive an empty bobbin therefrom and to return the bobbin carrier tube to its original position, and a guideway on said bobbin carrier tube for receiving the bobbin wound with yarn as it is discharged from the yarn guide tube.

8. Apparatus as claimed in claim 1 comprising a shaft slidably supported in the bobbin carrier tube for receiving the empty bobbin and means operatively associated with said shaft to slide the same upwards with the empty bobbin on said shaft to feed the empty bobbin to the yarn guide tube.

9. Apparatus as claimed in claim 1 comprising feeler means adjacent the yarn guide tube for reciprocating therein in gradually increasing strokes, with the yarn being wound on said bobbin, the feeler means contacting the yarn for winding the same on said bobbin with said yarn broken.

10. Apparatus as claimed in claim 1 comprising belt means coupled to the spinning tube to drive the same, the spinning tube including an upper flange, a pair of pulleys bearing against said spinning tube and supporting the upper flange thereof, and a second pair of corresponding pulleys beneath said first pair and bearing against said spinning tube.

11. Apparatus as claimed in claim 1 comprising means detachably connecting said bobbin to said yarn guide tube.

12. Apparatus as claimed in claim 11 wherein said means detachably connecting said bobbin to said yarn guide tube comprises a magnet on said yarn guide tube.

References Cited in the file of this patent UNITED STATES PATENTS 802,161 Gill Oct. 17, 1905 874,662 De Vito Dec. 24, 1907 2,232,490 Prince-Smith Feb. 18, 1941 

